GOEXPERIMENT=jsonv2 go test -bench=.

#BenchmarkMarshalV2-9             2123106               541.8 ns/op
#BenchmarkUnmarshalV2-9           1553101               778.6 ns/op

go test -tags=v1 -bench=.

#BenchmarkMarshal-9       3542091               323.1 ns/op
#BenchmarkUnmarshal-9     1349065               854.0 ns/op

